Winding mechanism



Fi lllllllllllll 54 ATT RNEY v United States Patent ffice i PatentedNov. 24, 1959` WINDING MECHANISM Application March 29, 1954, Serial No.419,507

2 Claims. (Cl. 242-55.11)

This invention relates to winding mechanism adapted to receive andaccumulate a length of flexible material and to maintain tension in thematerial as it is received and during the winding operation.

Many types of mechanisms perform operations on material in the form ofstrips, cords, tapes, strings, wire or cable, and at the termination ofthe operation the material is accumulated and stored on a reel, vbobbin,spindle or cylinder in one or more successive layers. In order toprevent the formation of a loop of material between the mechanism andthe take-up reel, tension is maintained by the reels on the material intransit between them and, when the mechanism speed is constant, thisinvolves driving the take-up reel at varying speeds as the diameter ofmaterial accumulated thereon varies.

Such take-up reels are commonly associated with motion picture camerasand projectors, wire drawing benches, automatic telegraph tapeperforators and transmitters, Wheatstone recorders, rolling mills, andmany other types of mechanisms. In all of them the take-up reel has arequirement that when the linear speed of the strip or wire is constantthe take-up reel must be made to rotate at speeds varying inversely withthe diameter of the material accumulated thereon.

Another equally important requirement for the takeup reel is that uponstopping of the mechanism the reel shall maintain tension on the wire orstrip until the mechanism has come to a complete rest. If the take-upreel should stop first, even by a fraction of a second tension would notbe maintained in the wire or strip entering it and in some cases slackwould be formed causing malfunction.

The formation of slack on stopping can be eliminated by driving bothmechanism and the take-up reel from the same mechanical power source. Itis, however, convenient in some cases to drive the take-up reelseparately because it simplies solution of the variable speedrequirement. However it aggravates the requirement that the take-up reelshall not stop before the mechanism. If, for example, the mechanism andthe take-up reel are rotated by two separte electric motors, and if whenthe mechanism is stopped by opening its motor circuit the take-up reelmotor circuit is also opened, either the mechanism or the take-up reelmay tend to stop first, depending on which has the less storedrotational energy or which has the greater friction. If the mechanismtends to stop first the tension in the strip or wire is maintained untilboth mechanism and reel stop. If, however, the take-up reel tends tostop first the mechanism will run after the take-up reel has stopped,causing loss of tension, slack, formation of a loop, or pile-up of thematerial. t

One obvious solution to this difliculty is to employ a slow releaserelay controlling the take-up motor. The instant invention employsanother solution which eliminates the use of the relay and which hasbeen found simpler in some cases.

In brief, the present invention provides a rotatable inertia element`having a relatively large amount of inertia, and a plurality of clutchand coupling devices to connect the driving element, the driven take-upreel and the rotatable element. The driving element stores somerotational energy in the rotatable element while driving the take-upreel, the coupling to the element being such as not to interfere withrequired rapid acceleration of the take-up reel when it is started fromrest. When electric power inputs to the mechanism and to the reeldriving element are cut off at the same time, the driven reel either isdeclutched from the driving element or remains coupled to it if thefrictional resistance of the driving element is low enough to permit. Inaddition the driven reel is clutched to the rotatable element so as tobe driven by it. The torque of the reel is then maintained by absorptionof energy from the inertia element until the mechanism shall have cometo a complete stop.

The principal purpose of this invention is to provide a windingmechanism Vwhich maintains continuous tension on the material woundthereon.

A more specific purpose of this invention is, to provide a windingmechanism which maintains tension on the' material being transferredthereto from a feeding mechanism until the feeding mechanism has come torest.

A further understanding of this invention may be secured from thedetailed description and drawings, in which:

Figure 1 illustrates a motion picture projector including a film striptake-up reel.

Figure 2 depicts a side'view of the take-up reel of Fig. l andassociated equipment for controlling the reel in accordance with oneembodimentof this invention.

Figure 3 is a detailed View of clutch suitable for use with theembodiment illustrated in Figs. l and 2.

Figure 4 illustrates another embodiment of this in-l vention.

Referring now to Fig. l, a motion picture projector includes a base 11with projection mechanism 12 secured thereon. The mechanism 12 containsa motor having an electric supply cable 13. Motion picture film to beexhibited is stored in drum 14 on a storage reel, and is drawn off byprojector 12. After passage of film 16 through the projector the film isreeled on the take-up reel 1'7 in take-up drum case 18. The take-up reelis driven by a gear motor 19, Fig. 2, through a self-containedspeed-reducing gear box 21 at an average reel speed of 70 r.p.m. Themotor 19 has a nominal speed of 1700 rpm. and is provided with a shaftat each end, its rotor shaft 22 projecting from the case end opposite tothe gear box. The shaft 22 carries a loose flywheel 23 the bore of whichforms a sleeve bearing having a running fit on the shaft 22. Theflywheel 23 is provided with an overrunning clutch 24 which can transmitpower from the ywheel to the shaft but which cannot transmit power fromthe shaft to the flywheel.

This overrunning clutch may be of any of the numerous Well-known forms,all having the characteristic that the clutch transmits power when thespeed of one member tends to be greater than that of the second member,and de clutches when the speed drops below that of the second member.One form of such clutch is illustrated in Fig. 3. The hub 25 of flywheel23 is bored to form a sleeve bearing having a running fit on shaft 22.This bearing has sufficient friction so that rotation of shaft 22 willgradually bring the flywheel up to shaft speed' but has small enoughfriction not to load the shaft materially in comparison with the loadimposed by the take-up reel. Rotation is in the direction of the arrow26. The clutch itself is formed of a spring steel five-turn wire helix27 having a free diameter slightly less than the shaft diameterencircling shaft 22, thus bearing on the shaft with a slight springpressure. One end of the spring is secured to the hub 24 by a screw 28,the other end being free.

In operation from rest, when shaft 2'2 commences to rotate it tends toturn spring 27 in the direction to loosen it, therefore the spring doesnot clutch the shaft. The slight friction of the spring on the shaft andfriction of the sleeve bearing gradually bring the flywheel up to thesame speed as the shaft. When power is removed from shaft 22 theflywheel tends to keep rotating at its attained speed because of itsangular momentum which is effectively greater than that of the shaft 22and attached parts. The shaft speed therefore tends to drop below thatof the flywheel. When, however, the shaft speed drops a very smallamount below that of the flywheel the relative rotation causes wire '27to seize the shaft the energy stored in the flywheel is communicated tothe shaft, driving it. The shaft 22 in turn applies torque to thetake-up reel 17, Fig. 1, motor 19, Fig. 2, having been deenergized, thetorque being sulllcient to maintain tension in the lm strip 16 and tocontinue winding it on the take-up reel until the projector 12 shallhave come to a complete stop.

Obviously, in place of the friction drive constituted by the sleevebearing of flywheel 23, any other form of friction drive may be employedsuch as the disc type which can be conveniently placed within hub 25. Byuse of a spring the disc pressure can be adjusted to adjust the timerequired for the flywheel to attain full speed. It is to be noted thatthe friction drive of the fly-v wheel through the sleeve bearing by theshaft is entirely distinct from the overrunning clutch wire 27 in bothstructure and function. The former drives the flywheel from the shaftand the latter drives the shaft from the flywheel.

In thus describing this embodiment of the invention it is assumed thatthe driving device, such as motor 1-9, has negligible internal frictionand therefore can remain coupled after power has been removed. A form ofthe invention in which the driving device drives through an overrunningclutch, so that this assumption need not be made, is illustrated in Fig.4. In this form the invention is applied to control of a take-up reel ordrum 29 on which a cord or wire 31 is taken up from a mechanism 32. Thedrum is driven by motive device 33. The mechanism 32 is so drivenrelative to driving device 33 actuating the take-up drum that thedescribed problem arises.

Driving device l33 drives an overrunning clutch 34 which clutches whenthe power is applied from shaft 36 and declutches when power is appliedfrom shaft 37. Shaft 37 actuates a speed changing gear 38 in which maybe included a slip clutch or a constant torque device as may be requiredby the dynamic characteristics of drum 29. Bevel gears 39 and 41 connectshaft 37 to shaft 42, although connection may alternatively be made byspur gears or otherwise. Shaft 412 drives a disc 43 which, together withfriction wheel 44, comprises a variable speed drive. Wheel 44 is securedto a shaft 46 rotatably bearing a sleeve 47 and having a collar 48pinned to its end. Between sleeve 47 and collar -48 four links 49, S1,`52 and 53 carry two ilyballs `54 and 56. A spring 57 urges the ballstogether. A loose ring 58 is rotatably held in a groove in sleeve 47,the ring 58 being secured to the frame. The combination of balls 54 andS6, their links and collars, spring 57 and shaft 46 thus forms aninertial governor. An oil or air dashpot 59 secured by a swivel 61 toshaft 46 retards shaft movement toward the left but does not retard itsmotion toward the right.

When the driving device 33 and mechanism 32 are at rest, ilyballs 54 and56 are in their innermost positions, wheel 44 is at its farthest rightposition and its point of contact with disc 43 is at a very slightdistance to the left of the disc center. Upon starting mechanism `32 anddriving device 33 the latter applies torque to drum 29 so as to`maintain tension in cord 31. The inertia of the flyballs 54 and 56 doesnot at starting appreciably load driving device 33 both because theyrotate at short radii and because they are driven with great speedreduction and by friction through disc 43 and wheel 44. However, as thellyballs gain angular momentum they move away from each other, extendingspring 57 and moving wheel 44 at a rate controlled by dashpot -59leftward toward the periphery of disc 43, increasing the speed of shaft46 and of the llyballs themselves.

When, during operation, power is removed from mechanism 32 and drivingdevice 33, the speed of driving device `33 and shaft 36 drops below thatof shaft 37 and clutch 34 declutches. Power stored in ilyballs l54 and56 because of their angular momentum now feeds from them throughvariable speed wheel 44 and disc 43, shaft 42, bevel gears 39 and 41,and gears 38 to drum 29, maintaining tension on cord 31. As the angularmomentum of lyballs S4 and 56 is expended they are drawn together byspring l57. This increases the speed ratio of drive through wheel 44 anddisc `413 so that the speed of drum 29 tends to be maintained in spiteof decreasing available energy in the tlyballs.

What is claimed is:

1. A winding mechanism comprising, a take-up reel for accumulating andstoring elongated flexible material, feeding means feeding said materialto said take-up reel, a drive shaft connected to said take-up reel, amotor, an overrunning clutch interconnecting said motor and said driveshaft, said clutch being arranged to apply power in the direction fromsaid motor to said take-up reel, an inertial governor, a wheel and discspeed changing mechanism connected to drive said governor, said speedchanging mechanism being connected to said drive shaft at a pointintermediate said overrunning clutch and said take-up reel whereby saidinertial means drives said take-up reel when the rate of decelerationthereof is greater than the rate of deceleration of said inertialgovernor.

2. A winding mechanism comprising, a take-up reel for accumulating andstoring elongated flexible material, feeding means feeding said materialto said take-up reel, a drive shaft for said take-up reel, a motor, anoverrunning clutch interconnecting said motor and drive shaft, saidclutch being arranged to apply power in the direction from said motor tosaid take-up reel, an inertial governor, and means coupling saidgovernor to said drive shaft subsequent to said clutch, whereby in onecondition of operation of said clutch power is applied from said motorto said take-up reel and said governor and in another condition ofoperation of said clutch, from said governor to said take-up reel.

References Cited in the file of this patent UNITED STATES PATENTS1,861,584 Readeker et al .lune 7, 1932 2,098,387 Heine Nov. 9, 19372,106,338 Black Jan. 25, 1938 2,113,256 Jeanne Apr. 5, 1938 2,123,084Tanson July 5, 1938 2,173,048 Von Madaler et al Sept. 12, 1939 2,233,284Collins Feb. 25, 1941 2,364,148 Kellogg Dec. 5, 1944 2,398,265 TylerApr. 9, 1946 2,496,977 Bechle IFeb. 7, 1950 FOREIGN PATENTS 103,863Australia Mar. l5, 1926

